Goran Ivanisevic will be flying into London later this week, although not in quite as much style as he flew out three years ago, when, as Wimbledon singles champion, he was borne back to Croatia on his friend Bernie Ecclestone's private plane. As Ecclestone and his Croatian wife, Slavica, watched the adulation which greeted Ivanisevic in his native town of Split - and which he reciprocated by throwing all his clothes bar his underpants into the crowd - they might have reflected that only once had they seen such intense patriotic fervour unleashed by a single sportsman. And in Ayrton Senna's case it was grief rather than joy that propelled the people on to the streets.

Ivanisevic is still frequently stopped by compatriots telling him how much he has inspired them, although his status as a national hero is somewhat out of kilter with the relatively humble position he fills these days as assistant to Croatia's Davis Cup captain, Nicky Pilic. Pilic has said that he will stand aside as soon as Ivanisevic wants to take on the captaincy himself, but Ivanisevic is in no rush.

"Maybe the year after next," he tells me. "I am learning whether I like it. It is good because men's tennis in Croatia was never better. We have three guys - [Mario] Ancic, [Ivan] Ljubicic and [Ivo] Karlovic - in the top 50, and four very good guys under 16. And we have Karolina Sprem, 18th in the world. In England they don't understand it. They invest so much money in tennis and here we invest hardly anything. They don't know how it happened." He smiles. "Nor do I."

I have an inkling that he might be part of the reason himself, such is the impact he has had on his fellow Croatians. In fact, several of them right now are looking at him, across the gloomy lobby of the Grand Hotel Bonavia in the Adriatic port of Rijeka, with expressions that can only be described as adoring.

Rijeka, where Croatia won their Davis Cup tie against Belgium, is about a two-hour drive from the capital Zagreb. Or would have been, had the main road through the mountains not been blocked by a landslide. In fact it has taken me more like six hours to get here from Zagreb, sitting queasily in the back of a rickety taxi, yet cheered by the prospect of meeting Ivanisevic, one of the more charismatic and enigmatic sportsmen of our times.

And surely the most superstitious. At Wimbledon in 2001 there were 10 rituals he felt he had to follow before each match, the oddest of which was watching Teletubbies . "My coach one day said: 'You have to watch this, this is so funny'. And I won my match that day. So then I couldn't stop. My favourite was the purple one, Tinky Winky." It's not every interview in the sports pages that features Tinky-Winky, I tell him. He looks faintly surprised.

He has agreed to meet me to help publicise the new phenomenon of Superset Tennis, the sport's wham-bam answer to Twenty20 cricket.

On Sunday, at Wembley Arena, a £250,000 prize awaits the player who comes through a sudden-death series of single-set matches. The idea is that old-timers can legitimately square up to younger men because the contest is more about skill than stamina. Thus John McEnroe is taking part, and Boris Becker, and Ivanisevic, as well as Tim Henman, Greg Rusedski and Ivanisevic's protégé, Ancic. Robby Ginepri and Tommy Ropredo make up the eight.

"It's a great thing," Ivanisevic says. His heavy accent is leavened by a light wit. "Especially for the guy who wins." He reckons to have played tennis only three times since he walked into retirement, the tumultuous applause of his beloved Centre Court crowd ringing in his ears, following his third-round elimination at Wimbledon three months ago. It would have been nice to go further in his valedictory Wimbledon, he says, but realistically he could not have scripted a better way to say goodbye.

"Third round, Centre Court, playing against [Lleyton] Hewitt, that crowd, it was the best scenario ever," he says. "In the second round I was struggling against [Filippo] Volandri on Court Two and I said to myself, 'I don't want to leave tennis losing against Volandri". He's a good player, but I wanted to win one more time. Then I got Hewitt. Hewitt was the worst opponent for me. He doesn't give you anything. [Andy] Roddick and even [Roger] Federer can blow you from the court but they miss some shots. Hewitt never misses. Everywhere I hit the ball, it came back."

Yet the same Hewitt, who thumped him 6-2, 6-3, 6-4, was himself obliterated by Federer in the US Open final. I am eager to hear the old champ's opinion of the new champ. Does he subscribe to the widespread view that Federer is destined to become the greatest tennis player of all time? "Yes," he says. "I hit with him when he was 15, during a tournament in Basle, and I knew then he would be good, but not this good. If he stays healthy, it will actually be a miracle if he doesn't win more Grand Slams than Pete [Sampras]. The way he picks his shots is unbelievable. He is fast, he has a great volley, a great serve, great backhand, great everything. If I was his coach, what can I tell him? He is a magician with a racket. Even when he is playing badly, which is rarely, he can still do things with his racket nobody else can do.

"I have played him twice, and lost both times. At Wimbledon this year I hit with him, because he was playing Bogdanovic and he wanted some practice with a leftie. I am much older but it was still an honour to practise with him. If I had a young player I was coaching I would take him first to watch Federer. But I would also take him to watch Henman, you know. The press in England is not fair to Henman. He is a great player. The way he plays volleys, he is like a professor of tennis."

It was Ivanisevic, of course, who denied the professor his magna cum laude moment, beating Henman following that infamous rain interruption in the one semi-final the Englishman seemed certain to win. Only three men know what it is like playing Henman in a semi-final at Wimbledon, before such a partisan crowd. I ask Ivanisevic to recall the experience. Did he shut out the relentless cries of "C'mon Tim!" or use them to motivate himself?

"Actually, I was surprised how many were shouting for me," he says. "It was not the worst time I had playing the crowd favourite. The worst was in '96, when [Stefan] Edberg announced that he was finishing his career, and then played me in the quarter-final of the US Open. I won the first point with an ace and nobody clapped. The second point I made a double fault and 19,000 people went crazy. And he wasn't even American.

"Henman I had played four times before and never beaten him. But I knew he would be very nervous. Everyone was thinking of him being in the final and maybe winning it, and that was my chance, right there. He was beating me badly - 6-0 in the third, 4-1 up in the fourth - when my friend up there sent the rain. I knew Henman was thinking about it more than me that night, which was good for me. And the next day when I won the tie-break in the fourth I knew the match was mine."

It might have happened more than three years ago, but for Ivanisevic the memories are fresh, not least because he refreshes them regularly by watching the video of his remarkable Monday final against Pat Rafter.

"Every time I watch it I sweat," he says, with a smile. "I think this time I might lose." It was his fourth Wimbledon singles final, but his first as a rank outsider, such was the slump he had suffered. "You know, my father had said that the best thing would happen to me when I had hit rock bottom. He was right. By 2001 I was ranked 125th in the world, and a lot of tournaments didn't even want to give me wild cards. At the Australian Open they put me on some court I couldn't even find. That is why people come to me telling me I changed their life, because I never gave up. And if it changed their life, imagine what it did to mine, finally getting to hold that trophy. But I nearly blew it. I reached those match points and then I couldn't get a serve in. If I had lost that match I would have given up. I would never have played tennis again."

As it turned out, the decision to retire was made in happier circumstances. Not that it isn't strange for him, waking up most days at home. Whichever of his homes - in Zagreb, Split and Monte Carlo - that might be.

"But it is great. My daughter is now 17 months old and she has changed my life more completely than giving up tennis. She changed my tennis, also. Before she was born, when I lost a match, I would be angry. After, I would just think about her and forget all about getting angry. One little smile changes everything."

Sweet. But I suspect we will still see Ivanisevic getting worked up on a tennis court, if only to give spectators what they expect. As well as the Superset event, he is committed to playing four exhibition matches between now and the end of the year. "And maybe next year I will start on the seniors' tour. I have to stay in tennis. I don't know what else I can do. I have some investments in property here, and Croatia is now a good market for tourism, but why do something that I don't really know anything about when I can make good money playing exhibition tennis?"

That there is such good money in tennis, he adds, is largely to do with Bjorn Borg. "We all owe him thanks. Before him, tennis was not well-paid. But he was the first superstar. He turned everything around. I practised with him when he made that comeback in Monte Carlo a few years ago. I was already eighth in the world but, Jesus, I was nervous just hitting with Borg."

It is comforting to find a modern sportsman acknowledging that his huge pay cheques have a provenance. I don't suppose David Beckham gives Jimmy Hill much credit for leading the campaign to abolish football's maximum wage. On which subject, Hadjuk Split's most famous fan doesn't want me to leave the Grand Hotel without hearing his views on the England football team.

"I love English football - I even follow the second and third divisions - but some of those players don't deserve to be in the team. They beat Croatia [in Euro 2004] but Croatia played very badly. After that, all the England players thought they were fantastic, and some of them were, like [Sol] Campbell and [Wayne] Rooney. But others, they are not so fantastic. And England, they always find a way to fail."

There's no arguing with that. We shake hands, and as we do so I ask Ivanisevic, a football nut and by all accounts a decent player, whether he would rather have been a professional footballer?

He ponders long and hard. "They have a much easier life. The tennis season is 11 months, almost 12 months if you play Davis Cup. You travel all the time, it is really boring, it is lonely, there are some nice tournaments but not many, and if you play bad someone is going to kick your ass. In football you can hide behind the rest of the team. But I think everyone is destined for one thing. And for me it was tennis."

Superset Tennis is live on Sky Sports on Sunday 3 October. For further information see www.superset-tennis.com.

Goran Ivanisevic

Life And Times

1971: Born in Split, Croatia [then Yugoslavia], 13 September.

1988: Turns professional, loses in first round in his first Wimbledon.

1989: Moves up from world No 371 to 40 after reaching seven quarter- finals. Wimbledon: second round.

1990: Wins first Tour singles title, in Stuttgart. Beaten by Boris Becker in five sets in Wimbledon semi-finals.